Features • Average temperature coefficient 50 ppm/°C • Temperature compensated for operation over the full temperature range • Programmable output voltage • Fast turn-on response • Low output noise • LM431 in micro SMD package • See AN-1112 for micro SMD considerations Description The LM431 is a 3-terminal adjustable shunt regulator with guaranteed temperature stability over the entire temperature range of operation. It is now available in a chip sized package (4-Bump micro SMD) using National's micro SMD package technology. The output voltage may be set at any level greater than 2.5V (VREF) up to 36V merely by selecting two external resistors that act as a voltage divided network. Due to the sharp turn-on characteristics this device is an excellent replacement for many zener diode applications.

Also Recommended LM4120 Lower Supply Current, Lower Temperature Coefficient & Enable Pin LM4125 Lower Supply Current, Lower Temperature Coefficient LM4128 Lower Supply Current, Lower Temperature Coefficient & Enable Pin LM4132 Lower Supply Current, Lower Temperature Coefficient & Enable Pin LMV431▲ Low Voltage (1.24V) MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

Typical Application click for larger image	Connection Diagram click for larger image
Typical Performance click for larger image

Datasheet

Title		Size	Date	Other Language
	LM431 Adjustable Precision Zener Shunt Regulator	872 Kbytes	18-Mar-05	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-71: Application Note 71 Micropower Circuits Using the LM4250 Programmable Op Amp	312 Kbytes	2-Oct-02

More Application Notes

Title		Size	Date	Other Language
	AN-1932: Application Note 1932 LMP2021MAEVAL - Bridge Sensor Instrumentation Amplifier Evaluation Board User Guide	176 Kbytes	10-Dec-08

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM431CCM/NOPB RoHS	SOIC NARROW	Lifetime buy Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 0 FUTURE Worldwide 50	$0.31 each at 1K+ pcs	rail of 95
LM431ACM/NOPB LM431ACM RoHS	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty AVNET-EM Worldwide 90 BRITESTONE South Korea 59 DIGIKEY Worldwide 1680 FUTURE Worldwide 1100 NEWARK Americas 1103 RS COMPONENTS Worldwide 60 TAYLOR Americas 5	$0.23 each at 1K+ pcs	rail of 95
LM431AIM/NOPB LM431AIM RoHS	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 285 AVNET-EM Worldwide 7000 DIGIKEY Worldwide 0 FARNELL Europe and Asia 1814 RS COMPONENTS Worldwide 30	$0.20 each at 1K+ pcs	rail of 95
LM431BCM/NOPB LM431BCM RoHS	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty AVNET-EM Worldwide 2620 DIGIKEY Worldwide 1296 FUTURE Worldwide 95	$0.25 each at 1K+ pcs	rail of 95
LM431BIM/NOPB LM431BIM RoHS	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 644 AVNET-EM Worldwide 1235 DIGIKEY Worldwide 680 FUTURE Worldwide 1100	$0.22 each at 1K+ pcs	rail of 95
LM431CIM/NOPB LM431CIM RoHS	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 475 AVNET-EM Worldwide 107 DIGIKEY Worldwide 1735 FUTURE Worldwide 1100	$0.34 each at 1K+ pcs	rail of 95
LM431BIMX/NOPB RoHS	SOIC NARROW	Lifetime buy Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$0.22 each at 1K+ pcs	reel of 2500
LM431CCMX/NOPB RoHS	SOIC NARROW	Lifetime buy Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$0.31 each at 1K+ pcs	reel of 2500
LM431CIMX/NOPB RoHS	SOIC NARROW	Lifetime buy Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$0.34 each at 1K+ pcs	reel of 2500
LM431ACMX/NOPB LM431ACMX RoHS	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 2500 FUTURE Worldwide 1100 KEIKONG Asia Pacific 12500 TAYLOR Americas 30000 TECHMOSA Asia Pacific 5000	$0.23 each at 1K+ pcs	reel of 2500
LM431AIMX/NOPB RoHS	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 5000 FUTURE Worldwide 1100	$0.20 each at 1K+ pcs	reel of 2500
LM431BCMX/NOPB LM431BCMX RoHS	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 7500 DIGIKEY Worldwide 0	$0.25 each at 1K+ pcs	reel of 2500
LM431ACM3/NOPB LM431ACM3 RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty AITG Asia Pacific 361 ARROW Worldwide 3000 DIGIKEY Worldwide 0 FARNELL Europe and Asia 2606 FUTURE Worldwide 1100 NEWARK Americas 1662 TAYLOR Americas 1995	$0.22 each at 1K+ pcs	reel of 1000
LM431AIM3/NOPB LM431AIM3 RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 569 DIGIKEY Worldwide 4727 FARNELL Europe and Asia 3945 FUTURE Worldwide 1100 KEIKONG Asia Pacific 65000 NEWARK Americas 172	$0.20 each at 1K+ pcs	reel of 1000
LM431BCM3/NOPB LM431BCM3 RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 1443 AVNET-EM Worldwide 1000 DIGIKEY Worldwide 4698 FARNELL Europe and Asia 4986 FUTURE Worldwide 1100 KEIKONG Asia Pacific 2000 NEWARK Americas 950	$0.23 each at 1K+ pcs	reel of 1000
LM431BIM3/NOPB LM431BIM3 RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty AVNET-EM Worldwide 1000 DIGIKEY Worldwide 5672 FUTURE Worldwide 1100 KEIKONG Asia Pacific 85000 NEWARK Americas 2380 RS COMPONENTS Worldwide 810	$0.22 each at 1K+ pcs	reel of 1000
LM431CCM3/NOPB LM431CCM3 RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 4000 DIGIKEY Worldwide 4049 FUTURE Worldwide 1100 NEWARK Americas 790	$0.31 each at 1K+ pcs	reel of 1000
LM431CIM3/NOPB LM431CIM3 RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 1000 AVNET-EM Worldwide 2000 DIGIKEY Worldwide 1947 FUTURE Worldwide 1100 NEWARK Americas 650 TECHMOSA Asia Pacific 3000	$0.37 each at 1K+ pcs	reel of 1000
LM431ACM3X/NOPB LM431ACM3X RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty AVNET-EM Worldwide 6000 DIGIKEY Worldwide 8183 FUTURE Worldwide 1100 KEIKONG Asia Pacific 3000 TECHMOSA Asia Pacific 60000	$0.22 each at 1K+ pcs	reel of 3000
LM431AIM3X/NOPB LM431AIM3X RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty AITG Asia Pacific 220 DIGIKEY Worldwide 0 FUTURE Worldwide 1100	$0.20 each at 1K+ pcs	reel of 3000
LM431BCM3X/NOPB RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty AITG Asia Pacific 1001 DIGIKEY Worldwide 0 FUTURE Worldwide 1100	$0.23 each at 1K+ pcs	reel of 3000
LM431BIM3X/NOPB LM431BIM3X RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 3000 DIGIKEY Worldwide 0 FUTURE Worldwide 1100 KEIKONG Asia Pacific 36000 TECHMOSA Asia Pacific 15000	$0.22 each at 1K+ pcs	reel of 3000
LM431CCM3X/NOPB LM431CCM3X RoHS	SOT-23	Full production Lead Time: 8 weeks	Distributor Region Qty AECO TECH Asia Pacific 1000 DIGIKEY Worldwide 0	$0.31 each at 1K+ pcs	reel of 3000
LM431CIM3X/NOPB LM431CIM3X RoHS	SOT-23	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 18000 AVNET-EM Worldwide 6000 DIGIKEY Worldwide 0 FUTURE Worldwide 1100	$0.37 each at 1K+ pcs	reel of 3000
LM431BIZ/NOPB RoHS		Lifetime buy Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$0.22 each at 1K+ pcs	box of 1800
LM431CCZ/NOPB LM431CCZ RoHS		Lifetime buy Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$0.31 each at 1K+ pcs	box of 1800
LM431ACZ/NOPB LM431ACZ RoHS		Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 1668 BRITESTONE South Korea 29749 DIGIKEY Worldwide 2779 FARNELL Europe and Asia 4850 FUTURE Worldwide 1100 RSL MICRO Asia Pacific 14400 TAYLOR Americas 26900	$0.22 each at 1K+ pcs	box of 1800
LM431AIZ/NOPB LM431AIZ RoHS		Full production Lead Time: 8 weeks	Distributor Region Qty ARROW Worldwide 3776 DIGIKEY Worldwide 827 FUTURE Worldwide 1100 KEIKONG Asia Pacific 89570 NEWARK Americas 1115 TAYLOR Americas 16	$0.20 each at 1K+ pcs	box of 1800
LM431BCZ/NOPB LM431BCZ RoHS		Full production Lead Time: 8 weeks	Distributor Region Qty AVNET-EM Worldwide 1598 DIGIKEY Worldwide 2108 FUTURE Worldwide 264 KEIKONG Asia Pacific 9600	$0.23 each at 1K+ pcs	box of 1800
LM431CIZ/NOPB RoHS		Full production Lead Time: 8 weeks	Distributor Region Qty DIGIKEY Worldwide 261	$0.34 each at 1K+ pcs	box of 1800

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM431AC MDC	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008
LM431AIBP	LM431AIM	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM431AIBPX	LM431AIM	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM431AITP	LM431AIM	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM431AITPX	LM431AIM	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM431BIMX	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431BIZ	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431CCM	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431CCMX	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431CCZ	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431CIMX	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431J-MLS	NONE	NONE	07 Jun 2001

Design Tools

Title	Size	Date
LM431AIBP Micro SMD Qualification Package	4172 Kbytes	17-Apr-2000

Reference Design

RD-163 - LM5072 12Vout 25W PoE PD Power Eval-Board for IP Camera

RD-171 - ± 5V Isolated, Low Noise Split Rail Generator (0.25A, 2.5W total)

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM431ACM	SLM	0	44046	0	0	3532500	1	1002356520
LM431ACM3	SLM	0	44046	0	0	3532500	1	1002356520
LM431ACM3X	SLM	0	44046	0	0	3532500	1	1002356520
LM431ACMX	SLM	0	44046	0	0	3532500	1	1002356520
LM431ACZ	SLM	0	44046	0	0	3532500	1	1002356520
LM431AIM	SLM	0	44046	0	0	3532500	1	1002356520
LM431AIM3	SLM	0	44046	0	0	3532500	1	1002356520
LM431AIM3X	SLM	0	44046	0	0	3532500	1	1002356520
LM431AIMX	SLM	0	44046	0	0	3532500	1	1002356520
LM431AIZ	SLM	0	44046	0	0	3532500	1	1002356520
LM431BCM	SLM	0	44046	0	0	3532500	1	1002356520
LM431BCM3	SLM	0	44046	0	0	3532500	1	1002356520
LM431BCM3X	SLM	0	44046	0	0	3532500	1	1002356520
LM431BCMX	SLM	0	44046	0	0	3532500	1	1002356520
LM431BCZ	SLM	0	44046	0	0	3532500	1	1002356520
LM431BIM	SLM	0	44046	0	0	3532500	1	1002356520
LM431BIM3	SLM	0	44046	0	0	3532500	1	1002356520
LM431BIM3X	SLM	0	44046	0	0	3532500	1	1002356520
LM431BIMX	SLM	0	44046	0	0	3532500	1	1002356520
LM431BIZ	SLM	0	44046	0	0	3532500	1	1002356520
LM431CCM	SLM	0	44046	0	0	3532500	1	1002356520
LM431CCM3	SLM	0	44046	0	0	3532500	1	1002356520
LM431CCM3X	SLM	0	44046	0	0	3532500	1	1002356520
LM431CCMX	SLM	0	44046	0	0	3532500	1	1002356520
LM431CCZ	SLM	0	44046	0	0	3532500	1	1002356520
LM431CIM	SLM	0	44046	0	0	3532500	1	1002356520
LM431CIM3	SLM	0	44046	0	0	3532500	1	1002356520
LM431CIM3X	SLM	0	44046	0	0	3532500	1	1002356520
LM431CIMX	SLM	0	44046	0	0	3532500	1	1002356520
LM431CIZ	SLM	0	44046	0	0	3532500	1	1002356520

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM431AC MDC	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008
LM431AIBP	LM431AIM	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM431AIBPX	LM431AIM	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM431AITP	LM431AIM	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM431AITPX	LM431AIM	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM431BIMX	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431BIZ	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431CCM	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431CCMX	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431CCZ	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431CIMX	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM431J-MLS	NONE	NONE	07 Jun 2001